Compound glasses are per se known. They usually consist of two spaced glasses firmly interconnected through an intermediate composition, for example, to provide a light-weight unbreakable arrangement. Already now, for example, in carriage construction, compound glasses are prepared by casting a casting resin between two glasses which may consist of flat glass (float glass) and/or plastic. The casting resin is then cured by UV irradiation, which causes bonding.
To achieve a thorough curing, very strong UV lamps and undesirably long irradiation times are required. This adds to the cost of compound glass arrangements and thus limits their utility. The same applies to applications other than compound glass production in which compositions are changed by UV irradiation.
UV-curing transparent paint and resin systems enjoy great popularity because mostly no solvents are necessary, shorter drying/curing times can be achieved, and the installation is often less expensive.
In the known systems, the cross-linking of the systems is initiated by UV light. In addition to ultraviolet light, UV lamps also emit some proportion of IR radiation (for example, metal-vapor lamps). To date, the IR radiation has not been well absorbed by the photoinitiators or other previously employed photoactive materials. As a rule, UV radiation is absorbed only shortly even by the photoinitiator, which quickly decomposes and subsequently does not absorb any longer.